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Seng-Jaw Soong

Publications and source records attributed to Seng-Jaw Soong.

15 recordsLinked to original sources
PubMed2006

Comparison of predictive values of two diagnostic tests from the same sample of subjects using weighted least squares.

Screening and diagnostic tests are important in disease prevention or control. The predictive values of positive and negative (PPV and NPV) test results are two of four operational characteristics of a screening test. We review an existing method based on the generalized estimating equation (GEE) methodology for comparing predictive values from the same sample of subjects and propose two Wald test statistics derived from the weighted least squares (WLS) method for the analysis of categorical data. Using these results, we propose sample size calculation formulae for this problem. Simulation studies are conducted to compare the performances of the two Wald test statistics (one based on the difference of two PPVs or NPVs, another based on the logarithm of the ratio of two PPVs or NPVs) and the score/Wald test statistic derived from GEE. We recommend using the difference-based WLS approach.

Angiography↗
PubMed2006

Impact of sentinel node status and other risk factors on the clinical outcome of head and neck melanoma patients.

OBJECTIVE: To determine the impact of sentinel lymph node (SLN) status and other risk factors on recurrence and overall survival in head and neck melanoma patients. DESIGN: The SLN Working Group, based in San Francisco, Calif, with its 11 member centers, the John Wayne Cancer Institute, and The University of Texas M. D. Anderson Cancer Center pooled data on 629 primary head and neck melanoma patients who had selective sentinel lymphadenectomy. A total of 614 subjects were analyzable. All centers obtained internal review board approval and adhered to the Health Insurance Portability and Accountability Act of 1996 regulations. A Cox proportional hazards model was used to identify factors associated with overall and disease-free survival. SETTING: Tertiary care medical centers. MAIN OUTCOME MEASURE: Clinical outcome of head and neck melanoma patients undergoing selective sentinel lymphadenectomy. RESULTS: Overall, 10.1% (n = 62) of the subjects had at least 1 positive node. Subjects with positive SLN status had significantly thicker tumors (mean thickness, 2.8 vs 2.1 mm; P < .001), and were more likely to have ulcerated tumors (P = .004). During the median follow-up of 3.3 years, the overall mortality from head and neck melanoma was 10%, with more than 20% experiencing at least 1 recurrence. Multivariate analysis showed that tumor site was an independent predictor of mortality; location on the scalp had a more than 3-fold (P < .001) greater mortality than tumors on the face. Tumor thickness was also an independent predictor of overall survival, and SLN status was the most important predictor of disease-free survival in the multivariate model (P < .001). Tumors on the scalp had the highest rate of recurrence, while those on the neck had the lowest. Tumor ulceration was the significant predictor of time to recurrence or disease-free survival (P < .001). CONCLUSION: In this multicenter study, SLN status and other risk factors have an effect on recurrence and/or overall survival.

Adult↗
PubMed2005

A population-based validation of the American Joint Committee on Cancer melanoma staging system.

PURPOSE: A major revision of the American Joint Committee on Cancer (AJCC) stages for melanoma was implemented in 2002 after its validation in multinational cohorts including patients from cancer centers and cooperative groups. This staging system has not been validated in a US population-based cohort. PATIENTS AND METHODS: We used 41,417 patients with primary invasive cutaneous melanoma diagnosed between 1988 and 2001 from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) cancer registry to validate the revised AJCC staging system. Survival rates computed from stage-specific Kaplan-Meier curves (time to melanoma-specific death) were compared with the survival rates from 17,600 patients in the original AJCC validation study. RESULTS: In the SEER cohort, 65% of reported melanomas were < or = 1.00 mm in thickness and 8.7% were more than 4.00 mm compared with 39% and 10% in the AJCC cohort (P < .001), respectively. AJCC stages were able to discriminate among SEER patient groups with different prognosis. However, SEER survival rates were significantly higher than those in the AJCC study and notably so in patients with T1a lesions (< or = 1 mm without ulceration). This population-specific effect remained significant after controlling for lesion thickness in all substages except stage IIA. CONCLUSION: Although this national population-based study validates the most recent revision of AJCC stages for melanoma, it emphasizes that survival rates are population specific and found them to be generally higher for SEER compared with AJCC patients. Population-specific survival rates should be used in study designs and decisions about patient-specific interventions.

Adolescent↗
PubMed2005

Clinical significance of occult metastatic melanoma in sentinel lymph nodes and other high-risk factors based on long-term follow-up.

Selective sentinel lymphadenectomy (SSL) following preoperative lymphoscintigraphy is the most significant recent advance in the management of patients with primary melanoma. This study evaluates the prognostic value of sentinel lymph node (SLN) status and other risk factors in predicting survival and recurrence in patients with primary cutaneous melanoma. From October 1993 to July 1998 a series of 412 patients with primary invasive melanoma underwent SSL at the UCSF/ Mt. Zion Melanoma Center. The outcome of 363 evaluable patients is summarized in this study. The factors related to survival and disease recurrence were analyzed by Cox proportional hazard regression models. The overall incidence of patients with positive SLNs was 18%. Over a median follow-up of 4.8 years, the overall mortality rate in patients with primary cutaneous melanoma was 18.7%, and 74 recurrences occurred (20.4%). Mortality was significantly related to SLN status [HR = 2.06; 95% Confidence interval (CI) 1.18, 3.58], angiolymphatic invasion (HR = 2.21; 95% CI 1.08, 4.55), ulceration (HR = 1.79; 95% CI 1.02, 3.15), mitotic index (HR =1.38; 95% CI 1.01, 1.90), and tumor thickness (HR = 2.20, 95% CI 1.21, 3.99). Factors significantly related to disease-free survival included SLN status (HR = 2.09; 95% CI 1.31, 3.34), tumor thickness (HR = 1.89; 95%. CI 1.20,2.98), and age (HR= 1.26 95% CI 1.08, 1.47). SLN status was the most significant factor for melanoma recurrence and death. Other important predictors include tumor thickness, ulceration, lymphatic invasion, and mitotic index.

Adult↗
PubMed2004

4-Hydroxybutyl(butyl)nitrosamine-induced urinary bladder cancers in mice: characterization of FHIT and survivin expression and chemopreventive effects of indomethacin.

The administration of 4-hydroxybutyl(butyl)nitrosamine (OH-BBN) to male B6D2F1 mice yielded a high incidence of large palpable urinary bladder cancers. Since prior studies demonstrated chemopreventive effects of non-steroidal anti-inflammatory drugs (NSAIDs), we further explored the efficacy of the NSAID indomethacin using different treatment regimens. OH-BBN was administered twice per week for 12 weeks (the first week of treatment was designated week 1). In Experiment I continual indomethacin treatment (20 mg/kg diet) was initiated either prior to (week -1) or following (week 13) OH-BBN dosing. Palpable bladder masses (subsequently diagnosed as cancers) developed in 32% of carcinogen-treated only mice by 32 weeks, while mice administered indomethacin either prior to or after OH-BBN developed palpable masses in 3 and 6% of the animals, respectively. In Experiment II mice were treated with indomethacin beginning 1 week after OH-BBN for either 12 weeks (limited treatment, weeks 13-24) or for 30 weeks (weeks 13-42). Continual treatment resulted in a 77% decrease in palpable bladder masses and an 82% decrease in all cancers (palpable and microscopic), while limited treatment decreased palpable masses by 48% but failed to decrease the number of bladder cancers (palpable plus microscopic). In Experiment III OH-BBN-treated mice were followed for 61 weeks. Palpable masses developed in 66% of control mice, while 26% of mice treated with indomethacin continually from 1 week after OH-BBN (weeks 13-61) developed palpable masses. A separate group in this study treated with indomethacin beginning when 5% of the mice had palpable bladder masses continued to develop new masses for an additional 4 weeks. By 6 weeks after beginning indomethacin treatment, however, these animals showed a profound decrease in the development of additional cancers. The expressions of FHIT and survivin in normal urinary bladder epithelium and in bladder cancers were determined by immunohistochemical analysis. FHIT was expressed at high levels in normal epithelium, but was minimally expressed in cancers, and even showed decreased expression in papillomas. The anti-apoptotic protein survivin was not expressed in normal bladder epithelium, but was variably expressed in cancers. FHIT and survivin expressions were similar in cancers from indomethacin-treated and non-treated mice.

Acid Anhydride Hydrolases↗
PubMed2004

Gene selection for oligonucleotide array: an approach using PM probe level data.

MOTIVATION: Analysis of oligonucleotide array data, especially to select genes of interest, is a highly challenging task because of the large volume of information and various experimental factors. Moreover, interaction effect (i.e. expression changes depend on probe effects) complicates the analysis because current methods often use an additive model to analyze data. We propose an approach to address these issues with the aim of producing a more reliable selection of differentially expressed genes. The approach uses the rank for normalization, employs the percentile-range to measure expression variation, and applies various filters to monitor expression changes. RESULTS: We compare our approach with MAS and Dchip models. A data set from an angiogenesis study is used for illustration. Results show that our approach performs better than other methods either in identification of the positive control gene or in PCR confirmatory tests. In addition, the invariant set of genes in our approach provides an efficient way for normalization.

Algorithms↗
PubMed2004

Randomized, controlled surgical trial of preoperative tumor curettage of basal cell carcinoma in Mohs micrographic surgery.

BACKGROUND: The use of preoperative tumor curettage in Mohs micrographic surgery has never been prospectively systematically assessed. OBJECTIVE: To assess the utility of preoperative tumor curettage in Mohs micrographic surgery for primary or recurrent, well-defined basal cell carcinoma less than 2 cm in diameter located on the head or neck. METHODS: Patients were randomized to either preoperative tumor curettage or control group and were compared in terms of percent surface area increase from tumor surface area to wound surface area, absolute surface area increase, number of tissue layers removed, types of repairs performed, and postoperative complications. Multivariate analysis was performed to see if tumor location, appearance (exophytic or flat), or histology affected any of the above. RESULTS: The preoperative tumor curettage group had a 399% (95% confidence interval [CI] 346-452) mean surface area increase from tumor to wound surface area versus 263% (95% CI 216-311) for control group (P=.0002). The preoperative tumor curettage group had a mean absolute surface area increase of 1.78 cm2 (95% CI 1.57-1.99) versus 1.40 cm2 (95% CI 1.15-1.65) for control group (P=.02). The preoperative tumor curettage group had fewer tissue layers removed (P=.3). Preoperative tumor curettage had no effect on types of repairs performed or number or type of postoperative complications. Tumor appearance and histology had no effect on any of the above end points. CONCLUSION: Preoperative tumor curettage was associated with significantly greater percent surface area increase and absolute surface area increase from tumor surface area to wound surface area. This difference did not affect type of repair performed or postoperative complications.

Basal Cell Carcinoma↗
PubMed2003

Tumor mitotic rate is a more powerful prognostic indicator than ulceration in patients with primary cutaneous melanoma: an analysis of 3661 patients from a single center.

BACKGROUND: The current study was performed to determine whether tumor mitotic rate (TMR) is a useful, independent prognostic factor in patients with localized cutaneous melanoma. METHODS: From the Sydney Melanoma Unit database, 3661 patients with complete clinical information and details of primary tumor thickness, ulcerative state, and TMR were studied. TMR was expressed as mitoses per mm(2) in the dermal part of the tumor in which most mitoses were seen, as recommended in the 1982 revision of the 1972 Sydney classification of malignant melanoma. To determine which was the more prognostically useful method of grouping TMR, two separate methods (A and B) were used. Factors predicting melanoma-specific survival were analyzed using the Cox proportional hazards regression model. RESULTS: Patients with a TMR of 0 mitoses/mm(2) had a significantly better survival than those with 1 mitosis/mm(2) (P < 0.0001) but no significant survival differences were recorded for the stepwise increases from 1-2, 2-3, 3-4, and 4-5/mm(2). Tumor thickness, ulceration, and TMR were closely correlated, whether TMR was grouped using Method A (0, 1-4, 5-10, and >/= 11 mitoses/mm(2)) or Method B (0-1, 2-4, and >/= 5 mitoses/mm(2)). However, Cox regression analysis indicated that the TMR was a highly significant independent prognostic factor, particularly when grouped according to Method A, in which it was second only to tumor thickness as the most powerful predictor of survival (P < 0.0001). CONCLUSIONS: TMR is an important independent predictor of survival for melanoma patients. If confirmed by studies from other centers, it has the potential to further improve the accuracy of melanoma staging, as well as to define more rigidly the risk categories for patients entering clinical trials.

Adolescent↗
PubMed2003

Phase 1 trial of combined chemotherapy and reirradiation for recurrent unresectable head and neck cancer.

BACKGROUND: The management of recurrent unresectable head and neck cancer remains a challenging problem. Based on the circadian rhythm concept, we sought to determine the maximum tolerated dose (MTD) of infusional 5-flourouracil (5-FU), hydroxyurea (HU), and reirradiation (RT). METHOD: Bolus 5-FU was escalated from 300 mg/m(2)/d to a 10-hour infusion beginning at midnight, increased at 150 mg/m(2)/d increments. HU, 1.5 g, remained constant. Chemotherapy was given on weeks 1 and 4. RT was given daily, 2.0 Gy per fraction on weeks 1 and 2 followed by a 1-week break, then hyperfractionated weeks 4 and 5, total dose 50 Gy. The goal was to deliver a continuous course of RT to 60 Gy after the MTD was determined with an additional week of chemotherapy. RESULTS: Six cohorts were treated to establish the 5-FU MTD of 900 mg/m(2)/d. The seventh cohort received continuous RT and 5-FU, 750 mg/m(2)/d, one dose level below the MTD. Two hematologic, three skin, and six mucosal >or= grade 3 toxicities were noted in 7 of 16 patients. The median survival was 10.2 months and the 1-year survival was 41%. The median survival for the entire group was 9.4 months, with a 1- and 2-year survival of 39% and 15%, respectively. CONCLUSION: RT can be given in a continuous fashion with concurrent 5-FU and HU. Because radiation sensitization should be achievable at nontoxic doses of 5-FU, we recommend 600 mg/m(2)/d in phase a II setting.

Adult↗
PubMed2003

New TNM melanoma staging system: linking biology and natural history to clinical outcomes.

The American Joint Committee on Cancer (AJCC) implemented major revisions of the melanoma TNM and stage grouping criteria in the recently published 6th edition of the Staging Manual. The new staging system better reflects independent prognostic factors that are used in clinical trials and in reporting the outcomes of various melanoma treatment modalities. Major revisions include: 1) melanoma thickness and ulceration but not level of invasion to be used in the T classification, 2) the number of metastatic lymph nodes rather than their gross dimensions and the delineation of microscopic vs. macroscopic nodal metastases to be used in the N classification, 3) the site of distant metastases and the presence of elevated serum lactic dehydrogenase (LDH) to be used in the M classification, 4) an upstaging of all patients with Stage I, II, and III disease when a primary melanoma is ulcerated, 5) a merging of satellite metastases around a primary melanoma and in transit metastases into a single staging entity that is grouped into Stage III disease, and 6) a new convention for defining clinical and pathological staging so as to take into account the new staging information gained from intraoperative lymphatic mapping and sentinel node biopsy.

Clinical Trials as Topic↗
PubMed2002

Conservative management of stage I endometrial carcinoma after surgical staging.

OBJECTIVE: The aim of this study was to determine the outcomes of Stage I endometrial carcinoma patients who are managed without adjuvant radiation after comprehensive surgical staging. METHODS: A computerized hospital database identified women diagnosed with adenocarcinoma of the endometrium from 1993 to 1998. A chart review identified 864 women as having primary surgery for adenocarcinoma of the endometrium. A total of 670 of 864 patients (78%) underwent comprehensive surgical staging with total hysterectomy, bilateral salpingo-oophorectomy, pelvic/para-aortic lymphadenectomy, and peritoneal cytology. After 57 patients with high-risk histologic subtypes were excluded, 613 patients remained for analysis. RESULTS: A total of 321 of 325 Stage IB patients (99%) did not receive adjuvant radiation. Fifteen of 321 patients (5%) recurred; 9 recurred in the pelvis or vagina. All 9 local recurrences were salvaged with whole pelvic radiation (XRT) and brachytherapy (BT). Seventy-seven patients were diagnosed with Stage IC disease; 53 (69%) received no adjuvant therapy. Four patients (8%) recurred, of which 2 recurred in the vagina. Three of 4 patients (75%) were salvaged, 2 with XRT/BT and 1 with surgery and chemotherapy. For all Stage I patients, the 5-year disease-free survival was 93% and the 5-year overall survival was 98%. CONCLUSIONS: Surgically staged patients with endometrial carcinoma confined to the uterine corpus have a small risk of recurrence and the majority of these recurrences can be salvaged with radiation therapy. Conservative management of Stage I endometrial carcinoma patients is an effective treatment strategy.

Adenocarcinoma↗
PubMed1993

The influence of staging laparotomy for cervical cancer on patterns of recurrence and survival.

A matched paired study of surgically staged and non-surgically staged patients with stage II and III cervical carcinoma from October 1974 through August 1987 was retrospectively performed. Eight of 55 (13.8%) had para-aortic lymph node involvement. After tailored extended field radiation 2/8 (25%) remain alive without evidence of disease. Patient survival although slightly in favor of the unstaged group was similar. Patterns of recurrence were similar amongst treatment groups. Para-aortic nodal recurrence, despite tailored radiation therapy, was identical (5.4%) in the staged and unstaged groups. Only one patient (not surgically staged) had an isolated para-aortic recurrence. With the morbidity of an operative procedure and similar survival rates and para-aortic nodal recurrence rates, the value of staging laparotomy in improved patient survival is questioned. Pelvic failure and other distant metastases continue to be the major sites of recurrences.

Journal Article↗
PubMedDate not supplied

Effectiveness of multiple internal standards: deuterated analogues of methylenedioxymethamphetamine, methylenedioxyamphetamine, methamphetamine, and amphetamine.

With the increasing abuse of methylenedioxymethamphetamine (MDMA) thereby requiring analysis, we have undertaken a systematic evaluation on parameters associated with the analysis of MDMA and related compounds, including methylenedioxyamphetamine (MDA), methamphetamine (MA), and amphetamine (AM). Parameters studied included three solid-phase adsorbents, five derivatization reagents, and four deuterated internal standards (IS). This report examines whether differences in quantitation data derived from the use of four ISs (one for each analyte) and two ISs (one for AM and MA, one for MDA and MDMA) are statistically significant. Two types of samples were included in this study. The first type (Type I) included four replicate sets of standard solutions prepared in urine matrix. All analytes (AM, MA, MDA, and MDMA) were included in all samples, and these analytes' concentrations in each set were at five levels (100, 250, 500, 1000, and 2000 ng/mL). Four deuterated analogues (MA-d(8), AM-d(8), MDMA-d(5), and MDA-d(5)) at 500 ng/mL were also included in all solutions. The second type of samples (Type II) included 25 case urine specimens. Most of these specimens contained MA/AM and/or MDMA/MDA. The specific objective of this study is to determine whether the 4-IS approach can indeed generate better quantitative data than a less-costly 2-IS. For Type I samples, where the true concentrations of the analytes are known, two-sample t-test is adapted to examine whether the two sets of prediction errors (i.e., known concentration minus calculated concentration) resulting from the 4-IS and the 2-IS approaches are statistically different. For Type II samples, where the analytes' true concentrations are unknown, one-sample t-test was adapted to determine whether the difference of the quantitation results derived from the 4-IS and the 2-IS approaches is statistically significant. Statistical analysis of quantitation data derived from Types I and II samples indicates that differences in MDA and MDMA concentrations resulting from the use of one (MDA-d(5) or MDMA-d(5)) or two (MDA-d(5) and MDMA-d(5)) are statistically nonsignificant. On the other hand, similar analysis on data derived from Type I samples indicate the use of the analytes' respective deuterated analogues as the ISs appear to generate better quantitative data for AM and MA.

3,4-Methylenedioxyamphetamine↗
PubMedDate not supplied

An evidence-based staging system for cutaneous melanoma.

A completely revised staging system for cutaneous melanoma was implemented in 2003. The changes were validated with a prognostic factors analysis involving 17,600 melanoma patients from prospective databases. This major collaborative study of predicting melanoma outcome was conducted specifically for this project, and the results were used to finalize the criteria for this evidence-based staging system. In fact, this was the largest prognostic factors analysis of prospectively followed melanoma patients ever conducted. Important results that shaped the staging criteria involved both the tumor-node-metastasis (TNM) criteria and stage grouping for all four stages of melanoma. Major changes in the staging include: (1) melanoma thickness and ulceration are the dominant predictors of survival in patients with localized melanoma (Stages I and II); deeper level of invasion (ie, IV and V) was independently associated with reduced survival only in patients with thin or T1 melanomas. (2) The number of metastatic lymph nodes and the tumor burden were the most dominant predictors of survival in patients with Stage III melanoma; patients with metastatic nodes detected by palpation had a shorter survival compared with patients whose nodal metastases were first detected by sentinel node excision of clinically occult or "microscopic" metastases. (3) The site of distant metastases (nonvisceral versus lung versus all other visceral metastatic sites) and the presence of elevated serum lactate dehydrogenase (LDH) were the dominant predictors of outcome in patients with Stage IV or distant metastases. (4) An upstaging was implemented for all patients with Stage I, II, and III disease when a primary melanoma is ulcerated by histopathological criteria. (5) Satellite metastases around a primary melanoma and in-transit metastases were merged into a single staging entity that is grouped into Stage III disease. (6) A new convention was implemented for defining clinical and pathological staging so as to take into account the new staging information gained from lymphatic mapping and sentinel node biopsy.

Databases, Factual↗